Cariba Creek (Visit this link)

All the thrills of the beach, ocean and river come to you at Cariba Creek. A huge indoor lagoon where the climate is always tropical. Crashing through water cannons and down slides, floating slowly along the Lazy River, or watching the world go by in our huge, steaming Volcanic Springs - everything that's wonderful about water is here.

http://www.alton-towers.co.uk/waterpark